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1.
J Appl Stat ; 51(2): 388-405, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38283054

RESUMO

Maternal depression and anxiety through pregnancy have lasting societal impacts. It is thus crucial to understand the trajectories of its progression from preconception to postnatal period, and the risk factors associated with it. Within the Bayesian framework, we propose to jointly model seven outcomes, of which two are physiological and five non-physiological indicators of maternal depression and anxiety over time. We model the former two by a Gaussian process and the latter by an autoregressive model, while imposing a multidimensional Dirichlet process prior on the subject-specific random effects to account for subject heterogeneity and induce clustering. The model allows for the inclusion of covariates through a regression term. Our findings reveal four distinct clusters of trajectories of the seven health outcomes, characterising women's mental health progression from before to after pregnancy. Importantly, our results caution against the loose use of hair corticosteroids as a biomarker, or even a causal factor, for pregnancy mental health progression. Additionally, the regression analysis reveals a range of preconception determinants and risk factors for depressive and anxiety symptoms during pregnancy.

2.
Int J Psychiatry Med ; 58(3): 231-248, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35499173

RESUMO

OBJECTIVE: Balint groups provide a safe space for clinicians to discuss difficult cases, with the aim of deepening the clinician-patient relationship and providing space for self-introspection and personal development. During this COVID-19 period, mental health clinicians need a platform to undergo professional supervision and peer learning sessions, which can be provided for by Tele-Balint sessions. This study aims to understand the workings of Balint groups in a multi-disciplinary team, through exploring the experience and perceptions of mental health clinicians in a tertiary obstetrics- and paediatrics-focused hospital in Singapore towards Tele-Balint groups, and examining if these groups can address their professional needs. METHOD: A mixed-methods study was conducted. 26 mental health clinicians who had participated in Tele-Balint groups since March 2020 completed a semi-structured questionnaire, and 12 of them were interviewed. Qualitative analysis of interview transcripts was performed. RESULTS: Qualitative analysis revealed 5 themes. The first 4: professional and personal growth of clinicians, providing emotional support to clinicians, burnout in clinicians: what contributes and what helps, and psychological safety, address whether Tele-Balint groups meet clinicians' needs. The last theme, evolution of nature of Balint groups, addresses whether Tele-Balint groups meet clinicians' needs during the time of a pandemic. CONCLUSIONS: Tele-Balint group participation was found to be beneficial in facilitating personal and professional growth, providing emotional support and preventing burnout, despite some limitations. Members should maintain flexibility towards the Balint process, in order to accommodate others who have differing needs, especially in a multi-disciplinary group.


Assuntos
Esgotamento Profissional , COVID-19 , Criança , Humanos , Esgotamento Profissional/psicologia
3.
Comput Struct Biotechnol J ; 20: 5256-5263, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36212528

RESUMO

Over the past decade, our understanding of human diseases has rapidly grown from the rise of single-cell spatial biology. While conventional tissue imaging has focused on visualizing morphological features, the development of multiplex tissue imaging from fluorescence-based methods to DNA- and mass cytometry-based methods has allowed visualization of over 60 markers on a single tissue section. The advancement of spatial biology with a single-cell resolution has enabled the visualization of cell-cell interactions and the tissue microenvironment, a crucial part to understanding the mechanisms underlying pathogenesis. Alongside the development of extensive marker panels which can distinguish distinct cell phenotypes, multiplex tissue imaging has facilitated the analysis of high dimensional data to identify novel biomarkers and therapeutic targets, while considering the spatial context of the cellular environment. This mini-review provides an overview of the recent advancements in multiplex imaging technologies and examines how these methods have been used in exploring pathogenesis and biomarker discovery in cancer, autoimmune and infectious diseases.

4.
Plant Cell ; 32(12): 3706-3722, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33004616

RESUMO

Heterosis or hybrid vigor is widespread in plants and animals. Although the molecular basis for heterosis has been extensively studied, metabolic and proteomic contributions to heterosis remain elusive. Here we report an integrative analysis of time-series metabolome and proteome data in maize (Zea mays) hybrids and their inbred parents. Many maize metabolites and proteins are diurnally regulated, and many of these show nonadditive abundance in the hybrids, including key enzymes and metabolites involved in carbon assimilation. Compared with robust trait heterosis, metabolic heterosis is relatively mild. Interestingly, most amino acids display negative mid-parent heterosis (MPH), i.e., having lower values than the average of the parents, while sugars, alcohols, and nucleoside metabolites show positive MPH. From the network perspective, metabolites in the photosynthetic pathway show positive MPH, whereas metabolites in the photorespiratory pathway show negative MPH, which corresponds to nonadditive protein abundance and enzyme activities of key enzymes in the respective pathways in the hybrids. Moreover, diurnally expressed proteins that are upregulated in the hybrids are enriched in photosynthesis-related gene-ontology terms. Hybrids may more effectively remove toxic metabolites generated during photorespiration, and thus maintain higher photosynthetic efficiency. These metabolic and proteomic resources provide unique insight into heterosis and its utilization for high yielding maize and other crop plants.


Assuntos
Vigor Híbrido , Metaboloma , Proteoma , Zea mays/genética , Metabolômica , Fotossíntese , Proteômica , Zea mays/metabolismo
5.
J Dev Behav Pediatr ; 40(9): 696-705, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31567856

RESUMO

OBJECTIVE: Maternal anxiety is a well-known risk factor for early childhood behavior problems. In this study, we explore (1) whether parenting stress mediates this relation and also (2) whether child factors, namely self-regulation, modify the influence of maternal well-being on child externalizing and internalizing problems at 4 years of age. METHOD: Mothers taking part in the Growing Up in Singapore Towards Healthy Outcomes cohort completed the Spielberger State-Trait Anxiety Inventory when their children were 24 months of age. At 42 months of age, children performed a self-regulation task (n = 391), and mothers completed the Parenting Stress Index. When children were 48 months old, both parents completed the Child Behavior Checklist. RESULTS: As predicted, parenting stress mediated the relation between maternal trait anxiety and child externalizing and internalizing problems. This mediating effect was further moderated by child self-regulation. The indirect effect of maternal trait anxiety through parenting stress on child externalizing problems was stronger among children with low self-regulation. CONCLUSION: Parenting stress is an additional pathway connecting maternal trait anxiety and children's externalizing and internalizing behavior problems. The risk for child externalizing problems conveyed by elevated maternal trait anxiety and parenting stress may be buffered by better self-regulation in 4-year-olds. These results suggest that interventions that include decreasing parenting stress and enhancing child self-regulation may be important to limiting the transgenerational impact of maternal trait anxiety.


Assuntos
Ansiedade/epidemiologia , Sintomas Comportamentais/epidemiologia , Comportamento Infantil , Inibição Psicológica , Poder Familiar , Personalidade , Autocontrole , Estresse Psicológico/epidemiologia , Adulto , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Mães/estatística & dados numéricos , Comportamento Problema
6.
BMC Pediatr ; 19(1): 286, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31419962

RESUMO

BACKGROUND: Although infant media exposure has received attention for its implications on child development, upstream risk factors contributing to media exposure have rarely been explored. The study aim was to examine the relationship between maternal risk factors, infant television (TV) viewing, and later child cognition. METHODS: We used a prospective population-based birth cohort study, Growing Up in Singapore Towards healthy Outcomes (GUSTO), with 1247 pregnant mothers recruited in their first trimester. We first explored the relationship of infant TV exposure at 12 months and the composite IQ score at 4.5 years, as measured by the Kaufman Brief Intelligence Test, Second Edition (KBIT-2). Multivariable linear regressions were adjusted for maternal education, maternal mental health, child variables, birth parameters, and other relevant confounders. We then examined the associations of maternal risk factors with the amount of daily TV viewing of 12-month-old infants. Path analysis followed, to test a conceptual model designed a priori to test our hypotheses. RESULTS: The average amount of TV viewing at 12 months was 2.0 h/day (SD 1.9). TV viewing in hours per day was a significant exposure variable for composite IQ (ß = - 1.55; 95% CI: - 2.81 to - 0.28) and verbal IQ (ß = - 1.77; 95% CI: - 3.22 to - 0.32) at 4.5 years. Our path analysis demonstrated that lower maternal education and worse maternal mood (standardized ß = - 0.27 and 0.14, respectively, p < 0.01 for both variables) were both risk factors for more media exposure. This path analysis also showed that maternal mood and infant TV strongly mediated the relationship between maternal education and child cognition, with an exceptional model fit (CFI > 0.99, AIC 15249.82, RMSEA < 0.001). CONCLUSION: Infant TV exposure has a negative association with later cognition. Lower maternal education and suboptimal maternal mental health are risk factors for greater television viewing. Paediatricians have a role in considering and addressing early risks that may encourage television viewing.


Assuntos
Cognição , Tempo de Tela , Televisão/estatística & dados numéricos , Estudos de Coortes , Feminino , Humanos , Lactente , Masculino , Mães , Estudos Prospectivos , Fatores de Risco , Singapura
7.
ACS Med Chem Lett ; 9(7): 685-690, 2018 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-30034601

RESUMO

A series of biaryl chromans exhibiting potent and selective agonism for the GPR40 receptor with positive allosteric modulation of endogenous ligands (AgoPAM) were discovered as potential therapeutics for the treatment of type II diabetes. Optimization of physicochemical properties through modification of the pendant aryl rings resulted in the identification of compound AP5, which possesses an improved metabolic profile while demonstrating sustained glucose lowering.

8.
Neuropsychiatr Dis Treat ; 14: 919-925, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29636617

RESUMO

OBJECTIVES: Depressive symptoms are common during pregnancy and after childbirth. Estrogen levels fluctuate greatly during the course of pregnancy and may contribute to mood instability. The first aim of this case-control study was to investigate whether variants in the two estrogen receptor genes might contribute to the genetic susceptibility to pregnancy-related depression using controls that were screened for postnatal depression. The second aim was to uncover new variants in the two estrogen receptor genes. PATIENTS AND METHODS: Our study sample comprised 554 control subjects who had Edinburgh Postnatal Depression Scale (EPDS) scores below 7 at postnatal screening, and 159 patients with clinically diagnosed pregnancy-related depression. They were genotyped for four single-nucleotide polymorphisms (SNPs) and a dinucleotide repeat in the two genes: estrogen receptor α (ESR1) and estrogen receptor ß (ESR2). Fifty-six cases with personal and/or family history of depression of psychiatric disorders were selected for resequencing of the two genes. RESULTS: There was no statistically significant association with perinatal depression for all five variants. However, there was a trend toward higher frequencies of the genotypes associated with higher risk of depression for rs2077647 and rs4986938 in the case group. From resequencing, two novel ESR1 variants were identified from two different patients. CONCLUSION: Our study that used screened controls with low EPDS scores and cases with clinically diagnosed pregnancy-related depression could not replicate the association with depression for any of the SNPs for both genotype and allele frequencies. Two novel SNPs were identified and could be further investigated in a larger sample set.

9.
Ann Acad Med Singap ; 45(10): 466-470, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27832221

RESUMO

Postnatal depression is a major public health problem with clearly established adverse effects in child outcomes. This study examines the 4-year outcomes of a screening and early intervention programme, in relation to improvement in symptoms, functioning and health quality of life. Women were prospectively recruited up to 6 months postdelivery, using the Edinburgh Postnatal Depression Scale (EPDS) as a screening tool. High-scorers (EPDS >13), were offered psychiatric consultation, and those with borderline scores (EPDS 10-12) were provided counselling, and offered follow-up phone counselling by the assigned case manager. Outcome measures were obtained at baseline, and at 6 months or discharge if earlier, for levels of symptoms, functioning, and health quality of life. From 2008 to 2012, 5245 women were screened, with 307 (5.9%) women with EPDS >13 receiving intervention. Of these, 70.0% had depression, 4.6% anxiety and 3.4% psychosis. In the depression subgroup, the net change was improvement of 93.4% EPDS symptom scores, 92.2% Global Assessment of Functioning (GAF) scores, and 88.3% visual analogue scale (EQ VAS) health quality of life scores. Outcome scores across diagnostic categories demonstrated median changes of 10 points on EPDS, 20 points on GAF, and 25 points on EQ VAS, reflecting 73.9%, 36.4% and 41.7% change from baseline scores. Women with psychosis showed the biggest (80.0%) relative change in GAF functioning scores from baseline to discharge but had the lowest median change in EPDS symptom scores. A screening and intervention programme rightly-sited within an obstetric setting can improve clinical outcomes because of early detection and intervention.


Assuntos
Transtornos de Ansiedade/terapia , Depressão Pós-Parto/terapia , Intervenção Médica Precoce , Transtornos Psicóticos/terapia , Transtornos Puerperais/terapia , Adulto , Transtornos de Ansiedade/diagnóstico , Administração de Caso , Conselheiros , Atenção à Saúde , Depressão Pós-Parto/diagnóstico , Feminino , Nível de Saúde , Humanos , Programas de Rastreamento , Obstetrícia , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Psiquiatria , Transtornos Psicóticos/diagnóstico , Transtornos Puerperais/diagnóstico , Qualidade de Vida , Encaminhamento e Consulta , Singapura
10.
BMC Pregnancy Childbirth ; 15: 283, 2015 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-26518448

RESUMO

BACKGROUND: Depression during pregnancy or after childbirth is the most frequent perinatal illness affecting women of reproductive age. It could result in unfavourable outcomes for both women and their newborns. The incidence of perinatal depression is higher for those with family history of depression and other mental illness, suggesting the contribution of genetic factors. There is postulation that disruption or fluctuation of reproductive hormones could play a part in women who are sensitive to such changes. METHODS: This is a case-control study comparing the frequencies of candidate gene variants in patients with perinatal depression with controls. Patients of Chinese descent (N = 725) were recruited from the outpatient clinics of the hospital between 2010 and 2013. Controls were patients who came for postnatal consultations at the obstetrics clinics and scored ≤ 7 on the Edinburgh Postnatal Depression Scale (EPDS) at the postnatal screening programme of the hospital. Cases with confirmed diagnosis of clinical (major) depression related to pregnancy/postpartum were recruited from the hospital's outpatient clinic. Genomic DNA was extracted from saliva samples and genotyped for the polymorphisms of interest. Differences between groups were assessed by chi-square analysis. RESULTS: CRHR1 rs242939 and rs1876828 were not polymorphic in the study population. There was no statistically significant association of perinatal depression for CRHR1 rs242941 and GR rs41423247 (BclI). When all subjects were grouped based on family history of mental illness, there was a statistically significant association of CRHR1 rs242941 with family history regardless of depression status (P = 0.043). There was also a statistically significant difference for GR rs41423247 and regularity of menstrual periods (P < 0.000). Although not statistically significant, women with perinatal depression showed a trend towards higher frequency of self-reported menstrual irregularity. CONCLUSIONS: No evidence was found for the association of any of the genetic markers with perinatal depression in this study cohort. Instead, the possible genetic links were found in women with positive family history of mental illness and menstrual irregularity, suggesting these could be identifying risk markers for women.


Assuntos
Depressão Pós-Parto/genética , Predisposição Genética para Doença , Receptores de Hormônio Liberador da Corticotropina/genética , Receptores de Glucocorticoides/genética , Povo Asiático/genética , Estudos de Casos e Controles , China , Estudos de Coortes , Feminino , Genótipo , Humanos , Distúrbios Menstruais/complicações , Distúrbios Menstruais/genética , Transtornos Mentais/complicações , Transtornos Mentais/genética , Polimorfismo de Nucleotídeo Único , Gravidez , Fatores de Risco
11.
J Affect Disord ; 161: 43-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24751306

RESUMO

BACKGROUND: Depression during pregnancy or after childbirth is the most frequent perinatal illness affecting women. We investigated the length distribution of a trinucleotide repeat in RAI1, which has not been studied in perinatal depression or in the Chinese population. METHODS: Cases (n=139) with confirmed diagnosis of clinical (major) depression related to pregnancy/postpartum were recruited from the outpatient clinic. Controls were patients who came to the obstetrics clinics and scored <7 on the Edinburgh Postnatal Depression Scale (EPDS) (n=540). Saliva samples for DNA analysis, demographic information and self-reported frequency of occurrence of various premenstrual/menstrual symptoms were collected from all participants. Genomic DNA was extracted from saliva and relevant region sequenced to determine the number of CAG/CAA repeats that encodes the polyglutamine tract in the N terminal of the protein. Difference between groups was assessed by chi-square analysis for categorical variables and analysis of variance for quantitative scores. RESULTS: Compared to control subjects, patients with perinatal depression reported more frequent mood changes, cramps, nausea, vomiting, diarrhoea, and headache during premenstrual/menstrual periods (p=0.000). For the RAI1 gene CAG/CAA repeat, there was a statistically significant difference in the genotypic distribution between cases and controls (p=0.031). There was also a statistically significant association between the 14-repeat allele and perinatal depression (p=0.016). LIMITATIONS: Family history, previous mental illness, and physical and psychological symptoms during the premenstrual/menstrual periods were self-reported. EPDS screening was done only once for controls. CONCLUSIONS: The RAI1 gene polyglutamine repeat has a different distribution in our population. The 14-repeat allele is associated with perinatal depression and more frequent experience of physical and psychological symptoms during menstrual period.


Assuntos
Transtorno Depressivo/genética , Menstruação/genética , Peptídeos/genética , Fatores de Transcrição/genética , Adulto , Alelos , Sequência de Bases , DNA/genética , Primers do DNA , Feminino , Humanos , Gravidez , Transativadores
12.
Microvasc Res ; 79(1): 10-20, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19833141

RESUMO

We have previously demonstrated that implanted microvessels form a new microcirculation with minimal host-derived vessel investment. Our objective was to define the vascular phenotypes present during neovascularization in these implants and identify post-angiogenesis events. Morphological, functional and transcriptional assessments identified three distinct vascular phenotypes in the implants: sprouting angiogenesis, neovascular remodeling, and network maturation. A sprouting angiogenic phenotype appeared first, characterized by high proliferation and low mural cell coverage. This was followed by a neovascular remodeling phenotype characterized by a perfused, poorly organized neovascular network, reduced proliferation, and re-associated mural cells. The last phenotype included a vascular network organized into a stereotypical tree structure containing vessels with normal perivascular cell associations. In addition, proliferation was low and was restricted to the walls of larger microvessels. The transition from angiogenesis to neovascular remodeling coincided with the appearance of blood flow in the implant neovasculature. Analysis of vascular-specific and global gene expression indicates that the intermediate, neovascular remodeling phenotype is transcriptionally distinct from the other two phenotypes. Therefore, this vascular phenotype likely is not simply a transitional phenotype but a distinct vascular phenotype involving unique cellular and vascular processes. Furthermore, this neovascular remodeling phase may be a normal aspect of the general neovascularization process. Given that this phenotype is arguably dysfunctional, many of the microvasculatures present within compromised or diseased tissues may not represent a failure to progress appropriately through a normally occurring neovascularization phenotype.


Assuntos
Tecido Adiposo/irrigação sanguínea , Microvasos/transplante , Neovascularização Fisiológica , Animais , Apoptose , Movimento Celular , Proliferação de Células , Feminino , Regulação da Expressão Gênica , Proteínas de Fluorescência Verde/genética , Masculino , Camundongos , Camundongos SCID , Camundongos Transgênicos , Microcirculação , Neovascularização Fisiológica/genética , Fenótipo , Análise de Componente Principal , Fatores de Tempo , Transcrição Gênica
13.
J Steroid Biochem Mol Biol ; 110(3-5): 197-206, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18508261

RESUMO

Estradiol receptors (ER), ERalpha and ERbeta, are ligand-dependent transcription factors that regulate gene expression. Human and murine genetics suggest that ERalpha is the key target for estradiol action on bone, uterus and breast. To date, the molecular mode of action of estradiol and selective estradiol receptor modulators (SERMs) on bone is not fully understood. This is exemplified by a lack of in vitro assays that reliably predict SERM agonist activities in vivo. We hypothesized that ligand-dependent ERalpha transrepression, via protein-protein interactions at AP1, may predict estrogenic effects on bone. We modeled this using the MMP1 promoter, which encodes an AP1 binding site. We show that ICI-182780, raloxifene, 4-hydroxytamoxifen and estradiol all exhibit differential agonistic activities on the MMP1 promoter by suppressing activity by 20-80%. Transrepression efficacy and potency correlated with both uterotrophic (R(2)=0.98) and osteoprotective (R(2)=0.80) potential in the ovariectomized rat. This identifies MMP1 promoter transrepression as an agonist activity commonly shared by AF2 agonists and "antagonists" alike. Mutation analysis showed that the repression by estradiol and SERMs required correct amino acid sequences in the AF-2 domain. For instance, L540Q AF2 mutation did not alter responses to raloxifene, although it greatly increased responses to ICI-182780 (threefold) and reduced estradiol's effect by 20%. Furthermore, all tested ligands repressed the MMP1 promoter through the L540Q mutant with identical efficacy. Together, these data suggest that estradiol and SERMs share common agonist transcriptional activity via protein-protein interactions at AP1.


Assuntos
Osso e Ossos/efeitos dos fármacos , Receptor alfa de Estrogênio/agonistas , Metaloproteinase 1 da Matriz/genética , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Útero/efeitos dos fármacos , Motivos de Aminoácidos/fisiologia , Animais , Osso e Ossos/metabolismo , Regulação para Baixo/efeitos dos fármacos , Estradiol/farmacologia , Receptor alfa de Estrogênio/antagonistas & inibidores , Receptor alfa de Estrogênio/fisiologia , Feminino , Humanos , Metaloproteinase 1 da Matriz/metabolismo , Proteínas Mutantes/fisiologia , Regiões Promotoras Genéticas/efeitos dos fármacos , Estrutura Terciária de Proteína/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Células Tumorais Cultivadas , Útero/metabolismo
14.
J Biol Chem ; 281(12): 7825-33, 2006 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-16434401

RESUMO

Sialic acids are sometimes 9-O-acetylated in a developmentally regulated and cell-type-specific manner. Cells naturally expressing the disialoganglioside GD3 often O-acetylate the terminal sialic acid residue, giving 9-O-acetyl-GD3 (9AcGD3), a marker of neural differentiation and malignant transformation. We also reported that Chinese hamster ovary cells transfected with GD3 synthase can spontaneously O-acetylate some of the newly synthesized GD3. It is unclear whether such phenomena result from induction of the 9-O-acetylation machinery and whether induction is caused by the GD3 synthase protein or by the GD3 molecule itself. We now show that exogenously added GD3 rapidly incorporates into the plasma membrane of Chinese hamster ovary cells, and 9AcGD3 is detected after approximately 6 h. The incorporated GD3 and newly synthesized 9AcGD3 have a half-life of approximately 24 h. This phenomenon is also seen in other cell types, such as human diploid fibroblasts. Inhibitors of gene transcription, protein translation, or endoplasmic reticulum-to-Golgi transport each prevent induction of 9-O-acetylation, without affecting GD3 incorporation. Inhibition of the initial clathrin-independent internalization of incorporated GD3 also blocks induction of 9-O-acetylation. Thus, new synthesis of one or more components of the 9-O-acetylation machinery is induced by incorporation and internalization of GD3. Prepriming with structurally related gangliosides fails to accelerate the onset of 9-O-acetylation of subsequently added GD3, indicating a requirement for specific recognition of GD3. To our knowledge, this is the first example wherein a newly expressed or exogenously introduced ganglioside induces de novo synthesis of an enzymatic machinery to modify itself, and the first evidence for a mechanism of induction of sialic acid O-acetylation.


Assuntos
Gangliosídeos/química , Acetilação , Animais , Células CHO , Diferenciação Celular , Linhagem Celular , Membrana Celular/metabolismo , Transformação Celular Neoplásica , Clatrina/metabolismo , Cricetinae , Meios de Cultura/metabolismo , Meios de Cultura Livres de Soro/metabolismo , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Endocitose , Retículo Endoplasmático/metabolismo , Fibroblastos/metabolismo , Citometria de Fluxo , Complexo de Golgi/metabolismo , Humanos , Ácido N-Acetilneuramínico/química , Ácido N-Acetilneuramínico/metabolismo , Neurônios/metabolismo , Ligação Proteica , Ácidos Siálicos/química , Fatores de Tempo , Transcrição Gênica , Transfecção
15.
Mol Endocrinol ; 20(3): 516-33, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16223974

RESUMO

Estrogen receptor alpha (ERalpha) serine 118 (Ser118) phosphorylation modulates activation function-1 (AF1) function. Correct positioning of helix 12 promotes agonist-dependent recruitment of cyclin-dependent kinase-7 to catalyze this event. In this study we show robust cyclin-dependent kinase-7-independent, AF2 antagonist-induced Ser118 phosphorylation. Estradiol (E2) and ICI-182,780 (ICI-780) induce Ser118 phosphorylation of wild-type ERalpha and either of two helix 12 mutants, suggesting AF2-independent action, probably via shedding of 90-kDa heat shock protein. With E2 treatment, the predominantly nuclear, phosphorylated ERalpha in COS-1 cells is detergent soluble. Although levels of ICI-780-induced phosphorylation are profound, Ser118-phosphorylated ERalpha is aggregated over the nucleus or in the cytoplasm, fractionating with the cell debris and making detection in cleared lysates improbable. Selective ER modulators (SERMs) elicit a mixed response with phosphorylated ERalpha in both detergent-soluble and -insoluble compartments. Apparent ligand-induced loss of ERalpha protein from cleared lysates is thus due to ligand-induced redistribution into the pellet, not degradation. The COS-1 response to ICI-780 can be mimicked in MCF-7 cells treated with a proteasome inhibitor to block authentic ligand-induced degradation. With SERMs and antagonists, the magnitude of Ser118-phosphorylated receptor redistribution into the insoluble fraction of COS-1 cells correlates with the magnitude of authentic ERalpha degradation in MCF-7 cells. A strong inverse correlation with ligand-induced uterotropism in vivo (P < 0.0001) and direct correlation with AF2-independent transrepression of the matrix metalloprotease-1 promoter in endometrial cells in vitro are seen. These data suggest that ligand-induced Ser118 phosphorylation of ERalpha can be AF2 independent. Furthermore, they identify translocation of Ser118-phosphorylated ERalpha out of the nucleus, leading to cytoplasmic aggregation, as an antagonist pathway that may precede receptor degradation.


Assuntos
Antagonistas de Estrogênios/farmacologia , Receptor alfa de Estrogênio/antagonistas & inibidores , Receptor alfa de Estrogênio/metabolismo , Animais , Benzoquinonas , Células COS , Chlorocebus aethiops , Quinases Ciclina-Dependentes/efeitos dos fármacos , Quinases Ciclina-Dependentes/metabolismo , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Endométrio/citologia , Endométrio/efeitos dos fármacos , Estradiol/análogos & derivados , Estradiol/farmacologia , Receptor alfa de Estrogênio/agonistas , Feminino , Fulvestranto , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Lactamas Macrocíclicas , Metaloproteinase 1 da Matriz/efeitos dos fármacos , Metaloproteinase 1 da Matriz/genética , Tamanho do Órgão/efeitos dos fármacos , Fosforilação , Regiões Promotoras Genéticas , Quinonas/farmacologia , Ratos , Ratos Sprague-Dawley , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Serina/metabolismo , Útero/efeitos dos fármacos , Quinase Ativadora de Quinase Dependente de Ciclina
16.
J Cell Physiol ; 206(1): 175-80, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16021627

RESUMO

Thrombin is a serine protease that promotes platelet aggregation, blood coagulation, and tissue repair. A peptide derived from a non-proteolytically active region of thrombin, TP508, also promotes tissue repair and increased vascularity, yet does not activate platelet and inflammatory cascades. TP508 binds to cells with high affinity and stimulates cells independent of the proteolytically active thrombin receptors (PARs) and thus is considered to activate a non-proteolytically active receptor (non-PAR) pathway. Using a model of angiogenic sprouting, we further defined the angiogenic potential of TP508 and investigated the role of non-proteolytic, thrombin-mediated pathways in angiogenesis. The assay involves measuring angiogenic sprouting from cultured, intact microvessel fragments. In this assay, TP508 stimulated angiogenic sprouting to an extent similar to or greater than the potent angiogenic factor, VEGF. However, TP508 had no significant effect on the number of sprouts that formed per vessel. In contrast to TP508, proteolytically active receptor agonists had no effect or inhibited angiogenic sprouting. The increased sprouting activity stimulated by TP508 was VEGF dependent but did not involve an increase in VEGF mRNA expression above baseline levels. These results suggest that TP508 acts early in angiogenesis and directly on microvascular cells to accelerate sprouting, but not to induce more sprouting, in a manner different than the intact thrombin molecule.


Assuntos
Neovascularização Fisiológica/fisiologia , Peptídeos/metabolismo , Trombina/metabolismo , Animais , Vasos Sanguíneos/anatomia & histologia , Vasos Sanguíneos/metabolismo , Gelatinases/genética , Gelatinases/metabolismo , Técnicas In Vitro , Masculino , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Ligação Proteica , Ratos , Receptores de Trombina/agonistas , Receptores de Trombina/metabolismo , Transdução de Sinais/fisiologia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
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